BOTANY Higher Secondary Second Year - Textbooks Online

troubles. Stem is useful in the treatment of piles and its juice is used to
treat bleeding of nose.
4. Mimosa pudica
It belongs to Mimosaceae. The vernacular name of M. pudica in
tamil is ‘Thottal chinungi or Thottal surungi’. Its common english name
is Touch-Me-Not plant. It is a small herb with prickles which are erect or
curved. Leaflets are arranged in two rows containing 15 to 20 pairs.
Leaves are sensitive to touch. Flowers are pink and found in axillary
heads.
A decoction of the root obtained from this plant is used to relieve
asthma and diarrhoea. This plant is also useful for curing piles, minor
skin wounds and whooping cough. Mimosine, an alkaloid is extracted
from this plant.
5. Solanum nigrum
It belongs to Solanaceae. The vernacular name of S. nigrum in tamil
is manithakkali or manathakkali. Its trade name is black night shade. It
is an annual, erect, much branched and unarmed herb growing upto one
metre tall. Leaves are ovate without hairs. Flowers white borne on extra
axillary cymes. Fruits are globose and black coloured berry.
The extract of this herb is effective in the treatment of liver disorders
like cirrhosis of liver. This plant also cures fever, dysentery and promotes
urination. Active medicinal compounds like solanin and saponin are
extracted from this plant.
Microbes in medicine
Microbes like bacteria and fungi produce antibiotics. The substance
produced by a living organism, which inhibits the growth and metabolic
activities of pathogenic organisms (mostly bacteria) without affecting the
metabolism of host is called an antibiotic. Penicillin, streptomycin,
aureomycin and chloromycetin are some of the examples for antibiotics.
Penicillin is a well known antibiotic obtained from the blue green mold
called Penicillium notatum. When it is grown in culture medium, the mycelium
excretes an antibiotic substance called penicillin. The crude penicillin is
recovered, purified and dehydrated. It is effective against gram-positive
bacteria like Pneumonia bacteria. Streptomycin is obtained from the
filamentous bacterium, Streptomyces griseus, an actinomycetes. It cures
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